KR101953822B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a lower display panel including a lower insulating substrate and a lower reflective layer. An upper display panel including an upper insulating substrate and an upper reflective layer; A liquid crystal layer positioned between the lower reflective layer of the lower panel and the upper reflective layer of the upper panel; And a backlight unit disposed at a lower portion of the lower display panel and including a light source, wherein at least one of the lower display panel and the upper display panel has a pair of field generating electrodes formed thereon, Reflective layer and the liquid crystal layer form a micro cavity and a wavelength and a luminance of light emitted by resonating in the micro cavity are changed by an electric field generated by the electric field generating electrode.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

The present invention relates to a liquid crystal display device.

The liquid crystal display device is one of the most widely used flat panel display devices and is composed of two display panels having an electric field generating electrode such as a pixel electrode and a common electrode and a liquid crystal layer interposed therebetween.

A voltage is applied to the electric field generating electrode to generate an electric field in the liquid crystal layer, thereby determining the orientation of the liquid crystal molecules in the liquid crystal layer and controlling the polarization of the incident light to display an image.

Generally, in a liquid crystal display device, a color filter is used to display a color, and a polarizing plate is used to display white by transmitting light or blocking light to display black. The color filter and the polarizing plate used in this manner cause a decrease in the transmittance of light incident on the liquid crystal display device. That is, the color filter reduces the transmissivity by about 1/3, and the polarizer reduces the transmissivity by 1/2 or more.

Therefore, in order for a liquid crystal display device to display a constant luminance level, there is a disadvantage that it is necessary to be able to display a much higher level of luminance in the backlight.

Disclosure of Invention Technical Problem [8] The present invention provides a display device which does not use a color filter and a polarizing plate, thereby reducing the transmittance to a minimum.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a lower panel including a lower insulating substrate and a lower reflective layer; An upper display panel including an upper insulating substrate and an upper reflective layer; A liquid crystal layer positioned between the lower reflective layer of the lower panel and the upper reflective layer of the upper panel; And a backlight unit disposed at a lower portion of the lower display panel and including a light source, wherein at least one of the lower display panel and the upper display panel has a pair of field generating electrodes formed thereon, The reflective layer and the liquid crystal layer form a micro cavity, and the wavelength or brightness of light emitted by resonating in the micro cavity is changed by an electric field generated by the electric field generating electrode.

The voltage applied to the electric field generating electrode is adjusted to change the electric field to change the brightness of light emitted from the micro cavity to display the gray level.

The upper reflection layer and the lower reflection layer may include a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly laminated.

The unit laminate structure may have a triple layer structure in which the high refractive index layer is formed as two layers above and below and the low refractive index layer is interposed therebetween.

At least one of the upper reflection layer and the lower reflection layer may have the unit laminate structure formed up and down, and a metal layer may be formed therebetween.

The upper panel may further include a phosphor unit including a fluorescent layer.

The fluorescent layer may be excited by light of a specific wavelength provided by the light source to display a color.

The phosphor unit may further include a light transmitting layer positioned below the fluorescent layer and transmitting light having the specific wavelength.

The phosphor unit may further include a light blocking layer disposed on the fluorescent layer and blocking light of the specific wavelength.

The phosphor unit may be positioned between the upper insulating substrate and the upper reflective layer.

The phosphor unit may be located outside the upper insulating substrate.

Wherein the electric field generating electrode includes a common electrode formed on the upper panel and a pixel electrode formed on the lower panel, the common electrode is positioned on the upper reflective layer, and the pixel electrode is disposed under the lower reflective layer Can be located.

Wherein the electric field generating electrode includes a common electrode formed on the upper panel and a pixel electrode formed on the lower panel, the common electrode being located below the upper reflective layer, Can be located.

The lower panel may further include a second lower reflective layer positioned below the lower reflective layer, and the upper panel may further include a second upper reflective layer disposed on the upper reflective layer.

A lower dielectric layer positioned between the lower reflective layer and the second lower reflective layer, and an upper dielectric layer positioned between the upper reflective layer and the second upper reflective layer.

And an optical film attached to the outermost side of the upper display panel or the lowermost side of the lower display panel, wherein the optical film is not a polarizer.

The backlight unit may further include a light guide plate and a reflective sheet for transmitting the light provided from the light source to the lower display panel.

A protrusion pattern may be formed on the lower surface of the light guide plate.

The prism sheet may further include a prism sheet having a prism pattern on the light guide plate.

The light source may provide ultraviolet light or blue light.

As described above, since the color filter and the polarizing plate are not used, the transmittance is reduced to be small, and the transmittance of the liquid crystal display device can be improved. Further, it is possible to display the grayscale by adjusting the transmittance of light without using a polarizing plate in a liquid crystal display device.

1 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
2 and 3 are cross-sectional views illustrating a reflective layer according to an embodiment of the present invention.
4 to 6 are graphs showing the characteristics of the liquid crystal display device according to the embodiment of FIG.
7 is a cross-sectional view of a liquid crystal display device according to another embodiment of the present invention.
8 and 9 are graphs showing the characteristics of the liquid crystal display device according to the embodiment of FIG.
10 to 14 are sectional views of a liquid crystal display device according to another embodiment of the present invention.
15 to 18 are graphs showing the characteristics of the embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Now, a liquid crystal display according to an embodiment of the present invention will be described in detail with reference to FIG.

1 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.

1, a liquid crystal display device according to an embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 disposed therebetween, and a backlight unit 500 do.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. A lower panel 100 disposed thereon includes a TFT, a pixel electrode 191, and a lower layer 111 on a lower insulating substrate 110. The upper panel 200 disposed thereon includes a phosphor unit 230, a common electrode 270, and an upper reflective layer 211 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer.

First, the backlight unit 500 will be described.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530.

The light source 510 provides a light of a wavelength band that allows the fluorescent layer 231 formed on the upper panel 200 to be excited to display a color, and ultraviolet or blue light sources may be used depending on the embodiment.

In this embodiment, the light source 510 is positioned on the side surface of the light guide plate 520. The light guide plate 520 has a protrusion pattern formed on the lower surface thereof. Also, a reflective sheet 525 is disposed on the lower surface of the light guide plate 520, and a reflective sheet 525 may be disposed under the protruding pattern. The protrusion pattern of the light guide plate 520 and the reflective sheet 525 allow the light provided by the light source 510 to travel in the vertical direction to be provided to the lower panel 100 side.

A prism sheet 530 is disposed on the light guide plate 520. The prism sheet 530 includes a prism pattern. The prism pattern may have a pattern having a triangular cross-sectional structure extending in one direction. Depending on the embodiment, it may have a semicircular cross-sectional structure. Also, depending on the embodiment, it may have a hemispherical pattern. The prism pattern in this embodiment is located on the side of the light guide plate 520 on both sides of the prism sheet 530. Depending on the embodiment, two prism sheets 530 may be used, in which case the prism patterns may be positioned such that their extending directions are perpendicular to each other.

In some embodiments, the prism sheet 530 may not be included, and may further include additional films (brightness enhancement films, diffusers, etc.) in addition to the prism sheet 530.

Hereinafter, the lower display panel 100 will be described.

A gate line (not shown) including a gate electrode 124 is formed on a lower insulating substrate 110, and the gate line is covered with a gate insulating film 140.

A semiconductor 154 is formed on the gate insulating film 140 and a data conductor including a source electrode 173, a drain electrode 175 and a data line (not shown) covering a part of the semiconductor 154 is formed do. The data conductor is covered by the first protective film 180 and the drain electrode 175 of the data conductor is exposed by the contact hole formed in the first protective film 180. [

The gate electrode 124, the semiconductor 154, the source electrode 173 and the drain electrode 175 constitute a thin film transistor (TFT), and a channel of the thin film transistor (TFT) is formed in the semiconductor 154. The gate electrode 124 is a control terminal of the thin film transistor TFT and the source electrode 173 is an input terminal of the thin film transistor TFT and the drain electrode 175 is an output terminal of the thin film transistor TFT.

A pixel electrode 191 formed of a transparent conductive material such as ITO or IZO is formed on the first passivation layer 180 and is electrically connected to the drain electrode 175 exposed through the contact hole.

The control terminal of the thin film transistor (TFT) is connected to the gate line, and the input terminal is connected to the data line. The output terminal of the thin film transistor TFT is connected to the pixel electrode 191.

A gate insulating film 140 is formed between the gate line and the data line and is insulated and crossed.

A second passivation layer 185 is formed on the pixel electrode 191. The first passivation layer 180 and the second passivation layer 185 are formed of an insulating material including an inorganic material or an organic material. In some embodiments, the second protective film 185 may be omitted.

A lower reflective layer 111 is formed on the second protective film 185. The lower reflective layer 111 may have a structure including a multilayered dielectric or further include a metal film on a multilayered dielectric. 2 and 3 show the layered structure of the reflection layer, which will be described later.

An alignment film (not shown) may be formed on the lower reflective layer 111.

As described above, the polarizer is not attached to the lower panel 100.

Hereinafter, the upper panel 200 will be described.

A phosphor unit 230 is formed below the upper insulating substrate 210. The phosphor unit 230 includes a fluorescent layer 231 and a light blocking layer 233 located above the fluorescent layer 231 and a light transmitting layer 232 located below the fluorescent layer 231. The light blocking layer 233 blocks light in a wavelength band that excites the fluorescent layer 231 to prevent the fluorescent layer 231 from being excited by light provided from the outside, To transmit the light of the wavelength band that excites the light emitting layer 231. When the light source 510 provides ultraviolet light, the light blocking layer 233 is an ultraviolet blocking layer, the light transmitting layer 232 is an ultraviolet transmitting layer, and when the light source 510 provides blue light, 233 is a blue light blocking layer, and the light transmitting layer 232 is a blue light transmitting layer. The light transmitting layer 232 is located on the backlight unit 500 side in the fluorescent layer 231 and the light blocking layer 233 is located on the outside in the fluorescent layer 231. In some embodiments, at least one of the light-transmitting layer 232 and the light-blocking layer 233 may be removed.

A common electrode 270 and an upper reflective layer 211 are formed under the phosphor unit 230. The common electrode 270 is formed of a transparent conductive material such as ITO or IZO. The upper reflective layer 211 may include a multi-layer dielectric or may have a structure including a metal layer on a multi-layer dielectric, and may be formed in the same manner as the lower reflective layer 111. 2 and 3 show the layered structure of the reflection layer, which will be described later. In the embodiment of FIG. 1, the upper reflection layer 211 is located under the common electrode 270, but the position may be changed depending on the embodiment.

An alignment layer (not shown) may be formed under the upper reflective layer 211.

As described above, the polarizer is not attached to the upper display panel 200.

A liquid crystal layer 3 including liquid crystal molecules is disposed between the upper display panel 200 and the lower panel 100. The liquid crystal layer 3 may have a vertical alignment mode or a horizontal alignment mode, and a TN mode liquid crystal may also be used. A spacer (not shown) may be formed on the liquid crystal layer 3 to have a predetermined cell gap, and the spacer may be formed on the upper display panel 200 or the lower display panel 100.

The upper reflection layer 211 and the lower reflection layer 111 described above may have the structure of FIG. 2 or FIG.

2 and 3 are cross-sectional views illustrating a reflective layer according to an embodiment of the present invention.

In Fig. 2, an embodiment including a multilayer dielectric is shown, and in Fig. 3 an embodiment further comprising a metal film in the multilayer dielectric is shown.

2, the lower reflection layer 111 or the upper reflection layer 211 includes a dielectric layer H (hereinafter referred to as a high refractive index layer) having a high refractive index and a dielectric layer L (hereinafter referred to as a low refractive index layer) having a low refractive index. ), And has a structure in which a high refractive index layer and a low refractive index layer are repeatedly laminated (hereinafter referred to as a unit laminated structure). In the embodiment of FIG. 2, the unit laminate structure has a triple layer structure in which a high refractive index layer is formed as two layers above and below and a low refractive index layer is positioned therebetween. However, the unit laminate structure is not limited to a triple layer, and includes all cases in which two refractive index layers are repeatedly laminated in two or more layers.

3, the lower reflection layer 111 or the upper reflection layer 211 has a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly stacked, and a metal layer is formed therebetween . As shown in FIG. 3, the upper and lower unit laminated structures may have the same laminated structure or may have different laminated structures. The unit laminate structure is not limited to a triple layer, and includes all cases in which two refractive index layers are repeatedly laminated in two or more layers. In addition, the metal layer may be formed to have a thickness capable of transmitting light of a specific wavelength as well as reflection of light.

The liquid crystal display device as described above does not include a polarizing plate, thereby improving light efficiency. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency.

In addition, light is resonated in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, and light of a specific wavelength is transmitted through the upper reflective layer 211 and emitted. At this time, the wavelength transmitted by the change of the refractive index of the liquid crystal layer changes, and the amount of light (transmittance) transmitted through the wavelength changes, so that the gradation can be expressed. The characteristics of the liquid crystal display according to the embodiment of the present invention will be described with reference to FIGS. 4 to 6. FIG.

4 to 6 are graphs showing the characteristics of the liquid crystal display device according to the embodiment of FIG.

First, FIG. 4 is a graph of luminance versus wavelength, and is a graph showing the maximum luminance as 100 and a percentage.

FIG. 4 shows a graph of luminance versus wavelength of the light source used in the embodiment of the present invention, and the transmission characteristic of the light transmitting layer 232 used in FIG. 1 is also shown as "UV pass filter". In the embodiment of FIG. 1, ultraviolet light is used as a light source, and an ultraviolet ray transmitting layer is used as a light transmitting layer 232.

4 shows light emitted from a cavity in the micro cavity between the upper reflective layer 211 and the lower reflective layer 111 due to the refractive index N of the liquid crystal layer 3. The TN mode liquid crystal is used for the liquid crystal layer 3, and when the twist of the liquid crystal molecules is very large, the refractive index of the liquid crystal layer 3 is determined to be a value corresponding to an average refractive index of two refractive indices no and ne of the liquid crystal molecules . The refractive index of the liquid crystal layer 3 varies near the average refractive index of the two refractive indices no and ne due to the electric field between the pixel electrode 191 and the common electrode 270 and is transmitted through the microcavity The characteristics of light are shown in FIG. 4 through simulation.

The refractive index N of the liquid crystal layer 3 is 1.5 to 1.55, 1.65, the wavelength of the light transmitted through the microcavity increases. The characteristic shown in FIG. 4 is a graph simulating characteristics of light transmitted through a micro cavity, and therefore has a luminance higher than that of each wavelength provided by the light source.

However, since the actual luminance is limited by the luminance value of each wavelength provided by the light source, the luminance characteristic of light transmitted through a micro cavity is actually the same as that of FIG. In addition, FIG. 5 shows the result that light not corresponding to the transmission wavelength band is blocked by the light transmission layer 232. That is, the graph shown in FIG. 5 is a characteristic of light actually incident on the phosphor layer 231 of the phosphor unit 230.

5, the refractive index N of the liquid crystal layer 3 is 1.5 to 1.55, and the refractive index N of the liquid crystal layer 3 is 1.6. 1.65, the wavelength of the light transmitted through the microcavity increases, and the luminance of the light increases accordingly. The fluorescent layer 231 of the phosphor unit 230 emits light by the incident light to display the corresponding color, and the degree of light emission decreases as the incident brightness decreases.

Therefore, by adjusting the voltage of the pixel electrode 191 to adjust the refractive index N of the liquid crystal layer 3, the luminance of light transmitted through the microcavity is changed, and accordingly, the fluorescent layer 231 The gradation can be expressed by changing the degree of light emission of the light emitting element.

4 and 5, the TN mode liquid crystal layer 3 is used. However, in the case of using the liquid crystal layer 3 in the vertical alignment mode, the wavelength band of the transmitted light decreases as the refractive index N increases, It may have a characteristic opposite to that of FIG. That is, it is possible to vary depending on the characteristics of the liquid crystal layer 3 used.

Meanwhile, FIG. 6 illustrates a change in peak wavelength of light emitted from a micro cavity due to the angle of light incident on a micro cavity. Referring to FIG. In FIG. 6, the horizontal axis represents 0 when the light is incident vertically on the lower reflection layer 111, and the larger the angle, the more the incident light is obliquely incident. The vertical axis in Fig. 6 represents the variation value of the peak value of the transmission wavelength in nm and is a value calculated based on the light incident vertically.

That is, as the incident angle increases, that is, as the incident angle becomes oblique, the peak wavelength of light emitted from the microcavity changes. When the incident angle is about 20 degrees, the light is transmitted through the microcavity The wavelength of the light is varied by 10 nm. When the light is incident at a larger angle than the wavelength, the light does not proceed to the fluorescent layer 231 corresponding to the wavelength of the light blocked by the light transmitting layer 232.

As a result, there is an advantage that the problem of color parallax which is incident on the fluorescent layer 231 of the pixel due to the light to be provided to adjacent pixels among the light provided by the light source is reduced.

As described above, the light transmitting layer 232 of the phosphor unit 230 controls the light incident on the fluorescent layer 231 to induce the fluorescent layer 231 to emit light without noise. The light blocking layer 233 of the phosphor unit 230 also provides the light emitted by the fluorescent layer 231 to the user without noise.

Hereinafter, the embodiment of FIG. 7, which is another embodiment of the present invention, will be described.

The embodiment of FIG. 7 differs from the embodiment of FIG. 1 in that the phosphor unit 230 is located outside the upper insulating substrate 210.

7 is a cross-sectional view of a liquid crystal display device according to another embodiment of the present invention.

7, the liquid crystal display device according to the embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 disposed therebetween, and a backlight unit 500 do.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. A lower panel 100 disposed thereon includes a TFT, a pixel electrode 191, and a lower layer 111 on a lower insulating substrate 110. The upper panel 200 disposed thereon includes a phosphor unit 230, a common electrode 270, and an upper reflective layer 211 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer.

First, the backlight unit 500 will be described.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530.

The light source 510 provides light of a wavelength band that allows the fluorescent layer 231 formed on the upper panel 200 to display a color, and ultraviolet or blue light sources may be used depending on the embodiment.

In this embodiment, the light source 510 is positioned on the side surface of the light guide plate 520. The light guide plate 520 has a protrusion pattern formed on the lower surface thereof. Also, a reflective sheet 525 is disposed on the lower surface of the light guide plate 520, and a reflective sheet 525 may be disposed under the protruding pattern. The protrusion pattern of the light guide plate 520 and the reflective sheet 525 allow the light provided by the light source 510 to travel in the vertical direction to be provided to the lower panel 100 side.

A prism sheet 530 is disposed on the light guide plate 520. The prism sheet 530 includes a prism pattern. The prism pattern may have a pattern having a triangular cross-sectional structure extending in one direction. Depending on the embodiment, it may have a semicircular cross-sectional structure. Also, depending on the embodiment, it may have a hemispherical pattern. The prism pattern in this embodiment is located on the side of the light guide plate 520 on both sides of the prism sheet 530. Depending on the embodiment, two prism sheets 530 may be used, in which case the prism patterns may be positioned such that their extending directions are perpendicular to each other.

In some embodiments, the prism sheet 530 may not be included, and may further include additional films (brightness enhancement films, diffusers, etc.) in addition to the prism sheet 530.

Hereinafter, the lower display panel 100 will be described.

A gate line (not shown) including a gate electrode 124 is formed on a lower insulating substrate 110, and the gate line is covered with a gate insulating film 140.

A semiconductor 154 is formed on the gate insulating film 140 and a data conductor including a source electrode 173, a drain electrode 175 and a data line (not shown) covering a part of the semiconductor 154 is formed do. The data conductor is covered by the first protective film 180 and the drain electrode 175 of the data conductor is exposed by the contact hole formed in the first protective film 180. [

The gate electrode 124, the semiconductor 154, the source electrode 173 and the drain electrode 175 constitute a thin film transistor (TFT), and a channel of the thin film transistor (TFT) is formed in the semiconductor 154. The gate electrode 124 is a control terminal of the thin film transistor TFT and the source electrode 173 is an input terminal of the thin film transistor TFT and the drain electrode 175 is an output terminal of the thin film transistor TFT.

A pixel electrode 191 formed of a transparent conductive material such as ITO or IZO is formed on the first passivation layer 180 and is electrically connected to the drain electrode 175 exposed through the contact hole.

The control terminal of the thin film transistor (TFT) is connected to the gate line, and the input terminal is connected to the data line. The output terminal of the thin film transistor TFT is connected to the pixel electrode 191.

A gate insulating film 140 is formed between the gate line and the data line and is insulated and crossed.

A second passivation layer 185 is formed on the pixel electrode 191. The first passivation layer 180 and the second passivation layer 185 are formed of an insulating material including an inorganic material or an organic material. In some embodiments, the second protective film 185 may be omitted.

A lower reflective layer 111 is formed on the second protective film 185. The lower reflective layer 111 may have a structure including a multilayered dielectric or further include a metal film on a multilayered dielectric. 2 and 3 show the layered structure of the reflection layer, which will be described later.

An alignment film (not shown) may be formed on the lower reflective layer 111.

As described above, the polarizer is not attached to the lower panel 100.

Hereinafter, the upper panel 200 will be described.

A phosphor unit 230 is formed on the outer side of the upper insulating substrate 210. The phosphor unit 230 includes a fluorescent layer 231 and a light blocking layer 233 located above the fluorescent layer 231 and a light transmitting layer 232 located below the fluorescent layer 231. The light blocking layer 233 blocks light in a wavelength band that excites the fluorescent layer 231 to prevent the fluorescent layer 231 from being excited by light provided from the outside, To transmit the light of the wavelength band that excites the light emitting layer 231. When the light source 510 provides ultraviolet light, the light blocking layer 233 is an ultraviolet blocking layer, the light transmitting layer 232 is an ultraviolet transmitting layer, and when the light source 510 provides blue light, 233 is a blue light blocking layer, and the light transmitting layer 232 is a blue light transmitting layer. The light transmitting layer 232 is located on the backlight unit 500 side of the fluorescent layer 231 and contacts the outer surface of the upper insulating substrate 210. The light blocking layer 233 is located outside the fluorescent layer 231 do. In some embodiments, at least one of the light-transmitting layer 232 and the light-blocking layer 233 may be removed.

A common electrode 270 and an upper reflective layer 211 are formed under the upper insulating substrate 210. The common electrode 270 is formed of a transparent conductive material such as ITO or IZO. The upper reflective layer 211 may include a multi-layer dielectric or may have a structure including a metal layer on a multi-layer dielectric, and may be formed in the same manner as the lower reflective layer 111. 2 and 3 show the layered structure of the reflection layer, which will be described later. In the embodiment of FIG. 7, the upper reflection layer 211 is located under the common electrode 270, but the position may be changed depending on the embodiment.

An alignment layer (not shown) may be formed under the upper reflective layer 211.

As described above, the polarizer is not attached to the upper display panel 200.

A liquid crystal layer 3 including liquid crystal molecules is disposed between the upper display panel 200 and the lower panel 100. The liquid crystal layer 3 may have a vertical alignment mode or a horizontal alignment mode, and a TN mode liquid crystal may also be used.

The upper reflection layer 211 and the lower reflection layer 111 described above may have the structure of FIG. 2 or FIG.

2 and 3 are cross-sectional views illustrating a reflective layer according to an embodiment of the present invention.

In Fig. 2, an embodiment including a multilayer dielectric is shown, and in Fig. 3 an embodiment further comprising a metal film in the multilayer dielectric is shown.

Referring to FIG. 2, the lower reflection layer 111 or the upper reflection layer 211 includes a high refractive index layer and a low refractive index layer, and has a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly laminated. In the embodiment of FIG. 2, the unit laminate structure has a triple layer structure in which a high refractive index layer is formed as two layers above and below and a low refractive index layer is positioned therebetween. However, the unit laminate structure is not limited to a triple layer, and includes all cases in which two refractive index layers are repeatedly laminated in two or more layers.

3, the lower reflection layer 111 or the upper reflection layer 211 has a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly stacked, and a metal layer is formed therebetween . As shown in FIG. 3, the upper and lower unit laminated structures may have the same laminated structure or may have different laminated structures. The unit laminate structure is not limited to a triple layer, and includes all cases in which two refractive index layers are repeatedly laminated in two or more layers. In addition, the metal layer may be formed to have a thickness capable of transmitting light of a specific wavelength as well as reflection of light.

7, the phosphor unit 230 may be formed outside the upper insulating substrate 210 to allow the user to recognize the pattern of the phosphor unit 230, unlike the embodiment of FIG. In this case, an additional optical film may be attached to the outside of the phosphor unit 230 so that the user can not recognize the pattern of the phosphor unit 230. Various films can be used as the optical film, and a protective film, a coating film, an anti-fringe film for preventing foreign substances, or an anti-reflection (anti-reflection) -glare) and the like can be used. The above optical film can also prevent the pattern of the phosphor unit 230 from being visually recognized.

In a liquid crystal display device as described above, the liquid crystal display device as described above does not include a polarizing plate, thereby improving light efficiency. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency. In addition, light is resonated in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, and light of a specific wavelength is transmitted through the upper reflective layer 211 and emitted. At this time, the wavelength transmitted by the change of the refractive index of the liquid crystal layer changes, and the amount of light (transmittance) transmitted through the wavelength changes, so that the gradation can be expressed. The characteristics of the embodiment of FIG. 7 will also be described with reference to FIGS. 8 and 9. FIG.

8 and 9 are graphs showing the characteristics of the liquid crystal display device according to the embodiment of FIG.

8 is a graph of luminance versus wavelength, and is a graph showing the maximum luminance as 100 and a percentage.

FIG. 8 shows a graph of luminance versus wavelength of a light source used in an embodiment of the present invention. In the embodiment of Fig. 7, ultraviolet light was used as the light source.

8 illustrates light emitted by resonating light in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111 due to the refractive index N of the liquid crystal layer 3. The TN mode liquid crystal is used for the liquid crystal layer 3, and when the twist of the liquid crystal molecules is very large, the refractive index of the liquid crystal layer 3 is determined to be a value corresponding to an average refractive index of two refractive indices no and ne of the liquid crystal molecules . The refractive index of the liquid crystal layer 3 varies near the average refractive index of the two refractive indices no and ne due to the electric field between the pixel electrode 191 and the common electrode 270 and is transmitted through the microcavity The characteristics of the light are shown in FIG. 8 through simulation.

The refractive index N of the liquid crystal layer 3 is 1.5 to 1.55, 1.65, the wavelength of the light transmitted through the microcavity increases. The characteristic shown in FIG. 8 is a graph simulating characteristics of light transmitted through a micro cavity, and therefore has a luminance higher than the luminance per wavelength provided by the light source.

However, in practice, the luminance characteristic of the light transmitted through the micro cavity can not be greater than the luminance of the light source since the luminance is limited by the luminance value provided by the light source. (See FIG. 5)

Therefore, the result of FIG. 8 is different from the luminance of light actually transmitted through a micro cavity, and a decrease in luminance based on a graph of a light source is considered to be due to the fact that the light transmitted through a micro- Brightness.

The characteristics of Fig. 8 are similar to those of Fig. In other words, although there is a difference between the embodiments of FIGS. 1 and 7, there is no difference in the characteristics of light transmitted through a microcavity.

FIG. 9 is a graph showing the luminance of light transmitted through a microcavity with respect to the refractive index N of the liquid crystal layer 3, according to the embodiment of FIG.

As can be seen from the graph of FIG. 9, as the refractive index N of the liquid crystal layer 3 decreases, the luminance of the light transmitted through the microcavity also decreases. That is, the refractive index N of the liquid crystal layer 3 is 1.5 to 1.55, 1.6. As the size increases to 1.65, the brightness of the light transmitted through the microcavity also increases. The refractive index N of the liquid crystal layer 3 and the brightness of light transmitted through the micro cavity are not linearly related to each other but the refractive index N of the liquid crystal layer 3 is adjusted, the phosphor layer 231 of the phosphor unit 230 can control the amount of incident light. As a result, the degree to which the fluorescent layer 231 emits light can be controlled, thereby enabling the expression of gradation. The change of the refractive index N of the liquid crystal layer 3 is changed by the electric field generated due to the voltage difference between the pixel electrode 191 and the common electrode 270 and the voltage of the common electrode 270 can be constant, The voltage of the pixel electrode 191 can be adjusted to control the brightness of the transmitted light without using the polarizer.

8 and 9, the TN mode liquid crystal layer 3 is used. However, in the case of using the liquid crystal layer 3 in the vertical alignment mode, as the refractive index N increases, the wavelength band of the transmitted light decreases, It may have a characteristic opposite to that of FIG. That is, it is possible to vary depending on the characteristics of the liquid crystal layer 3 used.

Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 10 to 14. FIG.

10 to 14 are sectional views of a liquid crystal display device according to another embodiment of the present invention.

First, the embodiment of FIG. 10 will be described.

10 differs from the embodiment of FIG. 1 in that the phosphor unit 230 is located on the outer side of the upper insulating substrate 210 and unlike the embodiment of FIGS. 1 and 7, the pair of reflective layers 112 and 212, .

10, a liquid crystal display device according to an embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 disposed therebetween, and a backlight unit 500 do.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. The lower panel 100 disposed thereon includes a TFT, a pixel electrode 191 and first and second lower layers 111 and 112 on a lower insulating substrate 110. The upper panel 200 located on the upper panel 200 includes a phosphor unit 230, a common electrode 270 and first and second upper reflective layers 211 and 212 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer.

First, the backlight unit 500 will be described.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530.

The light source 510 provides light of a wavelength band that allows the fluorescent layer 231 formed on the upper panel 200 to display a color, and ultraviolet or blue light sources may be used depending on the embodiment.

In this embodiment, the light source 510 is positioned on the side surface of the light guide plate 520. The light guide plate 520 has a protrusion pattern formed on the lower surface thereof. Also, a reflective sheet 525 is disposed on the lower surface of the light guide plate 520, and a reflective sheet 525 may be disposed under the protruding pattern. The protrusion pattern of the light guide plate 520 and the reflective sheet 525 allow the light provided by the light source 510 to travel in the vertical direction to be provided to the lower panel 100 side.

A prism sheet 530 is disposed on the light guide plate 520. The prism sheet 530 includes a prism pattern. The prism pattern may have a pattern having a triangular cross-sectional structure extending in one direction. Depending on the embodiment, it may have a semicircular cross-sectional structure. Also, depending on the embodiment, it may have a hemispherical pattern. The prism pattern in this embodiment is located on the side of the light guide plate 520 on both sides of the prism sheet 530. Depending on the embodiment, two prism sheets 530 may be used, in which case the prism patterns may be positioned such that their extending directions are perpendicular to each other.

In some embodiments, the prism sheet 530 may not be included, and may further include additional films (brightness enhancement films, diffusers, etc.) in addition to the prism sheet 530.

Hereinafter, the lower display panel 100 will be described.

A gate line (not shown) including a gate electrode 124 is formed on a lower insulating substrate 110, and the gate line is covered with a gate insulating film 140.

A semiconductor 154 is formed on the gate insulating film 140 and a data conductor including a source electrode 173, a drain electrode 175 and a data line (not shown) covering a part of the semiconductor 154 is formed do. The data conductor is covered by the first protective film 180 and the drain electrode 175 of the data conductor is exposed by the contact hole formed in the first protective film 180. [

The gate electrode 124, the semiconductor 154, the source electrode 173 and the drain electrode 175 constitute a thin film transistor (TFT), and a channel of the thin film transistor (TFT) is formed in the semiconductor 154. The gate electrode 124 is a control terminal of the thin film transistor TFT and the source electrode 173 is an input terminal of the thin film transistor TFT and the drain electrode 175 is an output terminal of the thin film transistor TFT.

A pixel electrode 191 formed of a transparent conductive material such as ITO or IZO is formed on the first passivation layer 180 and is electrically connected to the drain electrode 175 exposed through the contact hole.

The control terminal of the thin film transistor (TFT) is connected to the gate line, and the input terminal is connected to the data line. The output terminal of the thin film transistor TFT is connected to the pixel electrode 191.

A gate insulating film 140 is formed between the gate line and the data line and is insulated and crossed.

A second passivation layer 185 is formed on the pixel electrode 191. The first passivation layer 180 and the second passivation layer 185 are formed of an insulating material including an inorganic material or an organic material. In some embodiments, the second protective film 185 may be omitted.

A second lower reflective layer 112 is formed on the second protective layer 185. A lower dielectric layer 113 is formed on the second lower reflective layer 112 and a first lower reflective layer 111 is formed on the lower dielectric layer 113. The first and second lower reflection layers 111 may have a structure including a multilayered dielectric or may further include a metal film on a multilayered dielectric. 2 and 3). The lower dielectric layer 113 is formed of a material having a dielectric constant, and may be an insulating material.

An alignment layer (not shown) may be formed on the first lower reflective layer 111.

As described above, the polarizer is not attached to the lower panel 100.

Hereinafter, the upper panel 200 will be described.

A phosphor unit 230 is formed on the outer side of the upper insulating substrate 210. The phosphor unit 230 includes a fluorescent layer 231 and a light blocking layer 233 located above the fluorescent layer 231 and a light transmitting layer 232 located below the fluorescent layer 231. The light blocking layer 233 blocks light in a wavelength band that excites the fluorescent layer 231 to prevent the fluorescent layer 231 from being excited by light provided from the outside, To transmit the light of the wavelength band that excites the light emitting layer 231. When the light source 510 provides ultraviolet light, the light blocking layer 233 is an ultraviolet blocking layer, the light transmitting layer 232 is an ultraviolet transmitting layer, and when the light source 510 provides blue light, 233 is a blue light blocking layer, and the light transmitting layer 232 is a blue light transmitting layer. The light transmitting layer 232 is located on the backlight unit 500 side of the fluorescent layer 231 and contacts the outer surface of the upper insulating substrate 210. The light blocking layer 233 is located outside the fluorescent layer 231 do. In some embodiments, at least one of the light-transmitting layer 232 and the light-blocking layer 233 may be removed.

A common electrode 270, first and second upper reflection layers 211 and 212, and an upper dielectric layer 213 are formed under the upper insulating substrate 210. The common electrode 270 is formed of a transparent conductive material such as ITO or IZO. The first and second upper reflective layers 211 and 212 may include a multi-layer dielectric or may include a metal layer in a multi-layer dielectric, and may be formed in the same manner as the lower reflective layer 111. 2 and 3), a common electrode 270 is disposed under the upper insulating substrate 210, a second upper reflective layer 212 is disposed under the common electrode 270, And a first upper reflective layer 211 is disposed under the first upper reflective layer 213. [

An alignment layer (not shown) may be formed under the first upper reflective layer 211.

As described above, the polarizer is not attached to the upper display panel 200.

A liquid crystal layer 3 including liquid crystal molecules is disposed between the upper display panel 200 and the lower panel 100. The liquid crystal layer 3 may have a vertical alignment mode or a horizontal alignment mode, and a TN mode liquid crystal may also be used.

The first and second upper reflective layers 211 and 212 and the first and second lower reflective layers 111 and 112 described above may have the structure of FIG. 2 or FIG.

2 and 3 are cross-sectional views illustrating a reflective layer according to an embodiment of the present invention.

In Fig. 2, an embodiment including a multilayer dielectric is shown, and in Fig. 3 an embodiment further comprising a metal film in the multilayer dielectric is shown.

Referring to FIG. 2, the first and second upper reflective layers 211 and 212 or the first and second lower reflective layers 111 and 112 include a high refractive index layer and a low refractive index layer. And has a unit laminate structure in which a refractive index layer is repeatedly laminated. In the embodiment of FIG. 2, the unit laminate structure has a triple layer structure in which a high refractive index layer is formed as two layers above and below and a low refractive index layer is positioned therebetween. However, the unit laminate structure is not limited to a triple layer, and includes all cases in which two refractive index layers are repeatedly laminated in two or more layers.

3, the first and second upper reflective layers 211 and 212 or the first and second lower reflective layers 111 and 112 may have a unit laminated structure in which a high refractive index layer and a low refractive index layer are repeatedly stacked And has a structure in which a metal layer is formed therebetween. As shown in FIG. 3, the upper and lower unit laminated structures may have the same laminated structure or may have different laminated structures. The unit laminate structure is not limited to a triple layer, and includes all cases in which two refractive index layers are repeatedly laminated in two or more layers. In addition, the metal layer may be formed to have a thickness capable of transmitting light of a specific wavelength as well as reflection of light.

In a liquid crystal display device as described above, the liquid crystal display device as described above does not include a polarizing plate, thereby improving light efficiency. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency. In addition, light is resonated in a micro cavity between the first upper reflective layer 211 and the first lower reflective layer 111, so that light of a specific wavelength passes through the first upper reflective layer 211 and is emitted. At this time, the wavelength transmitted by the change of the refractive index of the liquid crystal layer changes, and the amount of light (transmittance) transmitted through the wavelength changes, so that the gradation can be expressed.

The second lower reflection layer 112 and the second upper reflection layer 212 are formed in a micro cavity using a dielectric layer together with a lower dielectric layer 113 and an upper dielectric layer 213 located inside the second lower reflection layer 112 and the second upper reflection layer 212, . That is, the first and second lower reflection layers 111 and 112 and the lower dielectric layer 113 between the first and second lower reflection layers 111 and 112 form a microcavity, and the first and second upper reflection layers 211 and 212, The upper dielectric layer 213 also forms a microcavity. The additional microcavity is a microcavity (hereinafter also referred to as a dielectric microcavity) including a dielectric layer between the first upper reflective layer 211 and the first lower reflective layer 111 The micro cavity includes a liquid crystal layer 3, which is different from a liquid crystal layer micro cavity.

In the embodiment of FIG. 10, the wavelength of the light that is resonated and transmitted by the added dielectric micro-cavity can be adjusted to have a broader wavelength band. This will be described in detail with reference to FIG.

Hereinafter, the embodiment of FIG. 11 will be described.

11 differs from the embodiment of FIG. 1 in that optical films 221 and 121 are additionally formed on the outside of the display panels 100 and 200. FIG.

11, the liquid crystal display device according to the embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 disposed therebetween, and a backlight unit 500 do.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. A lower panel 100 disposed thereon includes a TFT, a pixel electrode 191, and a lower layer 111 on a lower insulating substrate 110. The upper panel 200 disposed thereon includes a phosphor unit 230, a common electrode 270, and an upper reflective layer 211 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer.

The backlight unit 500 of the embodiment of FIG. 11 is not different from the backlight unit 500 of FIG. 1 and further description is omitted.

Further, the lower panel 100 is also similar to the embodiment of Fig. However, there is a difference in that the optical film 121 is attached to the lowermost side (the backlight unit 500 side) of the lower panel 100.

The upper display panel 200 is similar to the embodiment of FIG. 1 but differs therefrom in that the optical film 221 is attached to the outermost side of the upper panel 200.

The optical films 121 and 221 are not polarizing plates, and various optical films can be used. For example, a protective film or a coating film for protecting the upper panel 200 or the lower panel 100, an anti-fringe film for preventing foreign substances, or an anti- An anti-reflection (anti-glare) film, or the like can be used.

In addition, the light blocking layer 233 and the light transmitting layer 232 included in the phosphor unit 230 may be removed from the phosphor unit 230 and formed at the positions of the optical films 121 and 221. That is, the phosphor unit 230 includes only the fluorescent layer 231, the light transmitting layer is formed of the optical film 121 of the lower panel 100, and the light blocking is performed by the optical film 221 of the upper panel 200 Layer may be formed.

In addition, according to an embodiment, only one of the two optical films 121 and 221 may be formed, and only the optical film 221 outside the upper panel 200 may be formed.

11, the upper reflective layer 211 and the lower reflective layer 111 have a structure similar to the embodiment of FIG. 2 or FIG.

11 has a micro-cavity structure as shown in FIG. 1, so that the liquid crystal display device as described above does not include a polarizing plate, thereby improving light efficiency. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency. In addition, light is resonated in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, and light of a specific wavelength is transmitted through the upper reflective layer 211 and emitted. At this time, the wavelength transmitted by the change of the refractive index of the liquid crystal layer changes, and the amount of light (transmittance) transmitted through the wavelength changes, so that the gradation can be expressed.

Hereinafter, the embodiment of FIG. 12 will be described.

12 has a structure in which the light blocking layer 233 and the light transmitting layer 232 are not included in the phosphor unit 230, but is omitted, as in the embodiment of FIG.

12, the liquid crystal display according to the exemplary embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 and a backlight unit 500 disposed therebetween, .

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. A lower panel 100 disposed thereon includes a TFT, a pixel electrode 191, and a lower layer 111 on a lower insulating substrate 110. The upper panel 200 disposed thereon includes a phosphor unit 230, a common electrode 270, and an upper reflective layer 211 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer. Here, the phosphor unit 230 does not include the light blocking layer 233 and the light transmitting layer 232.

The backlight unit 500 and the lower panel 100 of the embodiment of FIG. 12 are different from the backlight unit 500 of FIG. 1 and the lower panel 100, and further description is omitted.

1, the phosphor unit 230 of the upper panel 200 does not include the light blocking layer 233 and the light transmitting layer 232. [

In the embodiment of FIG. 12, the upper reflection layer 211 and the lower reflection layer 111 have a structure similar to the embodiment of FIG. 2 or 3.

12 has a micro-cavity structure as shown in FIG. 1, the liquid crystal display device as described above does not include a polarizing plate, thereby improving light efficiency. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency. In addition, light is resonated in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, and light of a specific wavelength is transmitted through the upper reflective layer 211 and emitted. At this time, the wavelength transmitted by the change of the refractive index of the liquid crystal layer changes, and the amount of light (transmittance) transmitted through the wavelength changes, so that the gradation can be expressed. Unlike FIG. 1, however, the light passing through the micro-cavity structure is not partially filtered by the light transmitting layer 232, and unnecessary light is also incident on the fluorescent layer 231. In addition, The fluorescent layer 231 is not filtered by the excitation light and the display quality may be deteriorated.

That is, the light transmitting layer 232 of the phosphor unit 230 controls the light incident on the fluorescent layer 231 to induce the fluorescent layer 231 to emit light without noise. However, even if the light transmitting layer 232 is not formed There is no problem in displaying an image as a display device although the display quality may be partially degraded. The light shielding layer 233 of the phosphor unit 230 also provides the light emitted by the fluorescent layer 231 to the user without noise. However, even if this layer is removed, the display quality may be partially degraded. However, There is no problem in displaying. Therefore, depending on the embodiment, the light transmitting layer 232 and the light blocking layer 233 of the phosphor unit 230 can be eliminated. In this case, the manufacturing cost is reduced.

In addition, the light blocking layer 233 and the light transmitting layer 232, which are omitted in FIG. 12, may be formed at the positions of the optical films 121 and 221 shown in FIG. 11 or may be formed at other positions.

Hereinafter, the embodiment of FIG. 13 will be described.

13 is different from the embodiment of FIG. 1 in that the upper reflective layer 211 is located on the upper side of the common electrode 270 and the lower reflective layer 111 is located on the lower side of the pixel electrode 191.

13, the liquid crystal display device according to the embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 disposed therebetween, and a backlight unit 500 do.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. A lower panel 100 disposed thereon includes a TFT, a pixel electrode 191, and a lower layer 111 on a lower insulating substrate 110. The upper panel 200 disposed thereon includes a phosphor unit 230, a common electrode 270, and an upper reflective layer 211 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer.

The backlight unit 500 of the embodiment of FIG. 13 is not different from the backlight unit 500 of FIG. 1 and further description is omitted.

The lower display panel 100 will be described.

A gate line (not shown) including a gate electrode 124 is formed on a lower insulating substrate 110, and the gate line is covered with a gate insulating film 140.

A semiconductor 154 is formed on the gate insulating film 140 and a data conductor including a source electrode 173, a drain electrode 175 and a data line (not shown) covering a part of the semiconductor 154 is formed do. The data conductor is covered by the first protective film 180 and the drain electrode 175 of the data conductor is exposed by the contact hole formed in the first protective film 180. [

The gate electrode 124, the semiconductor 154, the source electrode 173 and the drain electrode 175 constitute a thin film transistor (TFT), and a channel of the thin film transistor (TFT) is formed in the semiconductor 154. The gate electrode 124 is a control terminal of the thin film transistor TFT and the source electrode 173 is an input terminal of the thin film transistor TFT and the drain electrode 175 is an output terminal of the thin film transistor TFT.

The first passivation layer 180 is formed of an insulating material including an inorganic material or an organic material.

A lower reflective layer 111 is formed on the first protective layer 180. The lower reflective layer 111 may have a structure including a multilayered dielectric or further include a metal film on a multilayered dielectric. (See Figures 2 and 3)

The contact hole for exposing the drain electrode 175 is formed in the first protective film 180 and the lower reflective layer 111.

A pixel electrode 191 formed of a transparent conductive material such as ITO or IZO is formed on the lower reflective layer 111 and is electrically connected to the drain electrode 175 exposed through the contact hole.

The control terminal of the thin film transistor (TFT) is connected to the gate line, and the input terminal is connected to the data line. The output terminal of the thin film transistor TFT is connected to the pixel electrode 191.

A gate insulating film 140 is formed between the gate line and the data line and is insulated and crossed.

An alignment film (not shown) may be formed on the pixel electrode 191.

As described above, the polarizer is not attached to the lower panel 100.

Hereinafter, the upper panel 200 will be described.

A phosphor unit 230 is formed below the upper insulating substrate 210. The phosphor unit 230 includes a fluorescent layer 231 and a light blocking layer 233 located above the fluorescent layer 231 and a light transmitting layer 232 located below the fluorescent layer 231. The light blocking layer 233 blocks light in a wavelength band that excites the fluorescent layer 231 to prevent the fluorescent layer 231 from being excited by light provided from the outside, To transmit the light of the wavelength band that excites the light emitting layer 231. When the light source 510 provides ultraviolet light, the light blocking layer 233 is an ultraviolet blocking layer, the light transmitting layer 232 is an ultraviolet transmitting layer, and when the light source 510 provides blue light, 233 is a blue light blocking layer, and the light transmitting layer 232 is a blue light transmitting layer. The light transmitting layer 232 is located on the backlight unit 500 side in the fluorescent layer 231 and the light blocking layer 233 is located on the outside in the fluorescent layer 231. In some embodiments, at least one of the light-transmitting layer 232 and the light-blocking layer 233 may be removed.

An upper reflective layer 211 is formed under the phosphor unit 230. The upper reflective layer 211 may include a multi-layer dielectric or may have a structure including a metal layer on a multi-layer dielectric, and may be formed in the same manner as the lower reflective layer 111. (See Figures 2 and 3)

A common electrode 270 is formed under the upper reflective layer 211 and the common electrode 270 is formed of a transparent conductive material such as ITO or IZO.

An alignment film (not shown) may be formed under the common electrode 270.

As described above, the polarizer is not attached to the upper display panel 200.

A liquid crystal layer 3 including liquid crystal molecules is disposed between the upper display panel 200 and the lower panel 100. The liquid crystal layer 3 may have a vertical alignment mode or a horizontal alignment mode, and a TN mode liquid crystal may also be used.

The upper reflection layer 211 and the lower reflection layer 111 described above may have the structure of FIG. 2 or FIG. However, the lower reflection layer 111 of the embodiment of FIG. 13 includes contact holes.

In the liquid crystal display device of Fig. 13, the liquid crystal display device as described above does not include a polarizing plate, and the light efficiency is improved. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency. In addition, light is resonated in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, and light of a specific wavelength is transmitted through the upper reflective layer 211 and emitted. 1, the common electrode 270 and the pixel electrode 191 are present in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, Can be degraded. However, the embodiment of FIG. 13 can change the refractive index N of the liquid crystal layer 3 at a lower voltage than the embodiment of FIG. Even if the upper reflective layer 211 and the lower reflective layer 111 include a metal, there is an advantage that an electric field generated between the pixel electrode 191 and the common electrode 270 is less influenced.

In the embodiment shown in Fig. 13, the wavelength transmitted through the liquid crystal layer 3 changes due to the change in refractive index, and the amount of transmitted light (transmittance) changes as the wavelength changes.

Hereinafter, the embodiment of FIG. 14 will be described.

The embodiment of FIG. 14 differs from the embodiment of FIG. 1 in that the lower reflective layer 111 is located directly above the lower insulating substrate 110. On the other hand, the upper reflection layer 211 is located on the upper side of the common electrode 270, unlike the embodiment of FIG.

14, a liquid crystal display device according to an embodiment of the present invention includes a lower panel 100, an upper panel 200, a liquid crystal layer 3 disposed therebetween, and a backlight unit 500 do.

The backlight unit 500 includes a light source 510, a light guide plate 520, a reflection sheet 525, and a prism sheet 530. A lower panel 100 disposed thereon includes a TFT, a pixel electrode 191, and a lower layer 111 on a lower insulating substrate 110. The upper panel 200 disposed thereon includes a phosphor unit 230, a common electrode 270, and an upper reflective layer 211 on an upper insulating substrate 210. The lower display panel 100 and the upper display panel 200 do not include a polarizer.

The backlight unit 500 of the embodiment of FIG. 14 is not different from the backlight unit 500 of FIG. 1, so that further explanation is omitted.

The lower display panel 100 will be described.

A lower reflective layer 111 is formed on the lower insulating substrate 110. The lower reflective layer 111 may have a structure including a multilayered dielectric or further include a metal film on a multilayered dielectric. (See Figures 2 and 3)

A gate line (not shown) including a gate electrode 124 is formed on the lower reflective layer 111, and the gate line is covered with a gate insulating layer 140.

A semiconductor 154 is formed on the gate insulating film 140 and a data conductor including a source electrode 173, a drain electrode 175 and a data line (not shown) covering a part of the semiconductor 154 is formed do. The data conductor is covered by the first protective film 180 and the drain electrode 175 of the data conductor is exposed by the contact hole formed in the first protective film 180. [

The gate electrode 124, the semiconductor 154, the source electrode 173 and the drain electrode 175 constitute a thin film transistor (TFT), and a channel of the thin film transistor (TFT) is formed in the semiconductor 154. The gate electrode 124 is a control terminal of the thin film transistor TFT and the source electrode 173 is an input terminal of the thin film transistor TFT and the drain electrode 175 is an output terminal of the thin film transistor TFT.

The first passivation layer 180 is formed of an insulating material including an inorganic material or an organic material.

A pixel electrode 191 formed of a transparent conductive material such as ITO or IZO is formed on the first passivation layer 180 and is electrically connected to the drain electrode 175 exposed through the contact hole.

The control terminal of the thin film transistor (TFT) is connected to the gate line, and the input terminal is connected to the data line. The output terminal of the thin film transistor TFT is connected to the pixel electrode 191.

A gate insulating film 140 is formed between the gate line and the data line and is insulated and crossed.

An alignment film (not shown) may be formed on the pixel electrode 191.

As described above, the polarizer is not attached to the lower panel 100.

Hereinafter, the upper panel 200 will be described.

A phosphor unit 230 is formed below the upper insulating substrate 210. The phosphor unit 230 includes a fluorescent layer 231 and a light blocking layer 233 located above the fluorescent layer 231 and a light transmitting layer 232 located below the fluorescent layer 231. The light blocking layer 233 blocks light in a wavelength band that excites the fluorescent layer 231 to prevent the fluorescent layer 231 from being excited by light provided from the outside, To transmit the light of the wavelength band that excites the light emitting layer 231. When the light source 510 provides ultraviolet light, the light blocking layer 233 is an ultraviolet blocking layer, the light transmitting layer 232 is an ultraviolet transmitting layer, and when the light source 510 provides blue light, 233 is a blue light blocking layer, and the light transmitting layer 232 is a blue light transmitting layer. The light transmitting layer 232 is located on the backlight unit 500 side in the fluorescent layer 231 and the light blocking layer 233 is located on the outside in the fluorescent layer 231. In some embodiments, at least one of the light-transmitting layer 232 and the light-blocking layer 233 may be removed.

An upper reflective layer 211 is formed under the phosphor unit 230. The upper reflective layer 211 may include a multi-layer dielectric or may have a structure including a metal layer on a multi-layer dielectric, and may be formed in the same manner as the lower reflective layer 111. (See Figures 2 and 3)

A common electrode 270 is formed under the upper reflective layer 211 and the common electrode 270 is formed of a transparent conductive material such as ITO or IZO.

An alignment film (not shown) may be formed under the common electrode 270.

As described above, the polarizer is not attached to the upper display panel 200.

A liquid crystal layer 3 including liquid crystal molecules is disposed between the upper display panel 200 and the lower panel 100. The liquid crystal layer 3 may have a vertical alignment mode or a horizontal alignment mode, and a TN mode liquid crystal may also be used.

The upper reflection layer 211 and the lower reflection layer 111 described above may have the structure of FIG. 2 or FIG.

In the liquid crystal display device of Fig. 14, the liquid crystal display device as described above does not include the polarizing plate, and the light efficiency is improved. In addition, a fluorescent layer is used instead of the color filter to improve the light efficiency. In addition, light is resonated in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, and light of a specific wavelength is transmitted through the upper reflective layer 211 and emitted. 1, the common electrode 270, the pixel electrode 191, and the thin film transistor exist in a micro cavity between the upper reflective layer 211 and the lower reflective layer 111, Can be relatively lowered. However, the embodiment of FIG. 14 can change the refractive index N of the liquid crystal layer 3 with a lower voltage than the embodiment of FIG. Even if the upper reflective layer 211 and the lower reflective layer 111 include a metal, there is an advantage that an electric field generated between the pixel electrode 191 and the common electrode 270 is less influenced.

In the embodiment of FIG. 14, the wavelength transmitted through the liquid crystal layer 3 is changed by the change of the refractive index, and the amount of light (transmittance) transmitted by the wavelength changes.

Hereinafter, the characteristics of light in the embodiments of FIGS. 1, 7 and 10 to 14 will be described with reference to FIGS. 15 to 18. FIG.

15 to 18 are graphs showing the characteristics of the embodiment of the present invention.

First, the characteristics of the embodiments of FIGS. 1, 7, 11 to 14 including the liquid crystal layer micro-cavity and the embodiment having the dielectric micro-cavity in addition to those of FIGS. 15 and 16 will be described.

First, FIG. 15 shows the characteristics (light intensity according to wavelength) of light transmitted through the liquid crystal layer micro-cavities in Examples 1 and 2 (Examples of FIGS. 1 and 7) including only the liquid crystal layer micro- (Brightness according to the brightness). The upper and lower reflective layers 211 and 111 used in FIG. 15 had a structure as shown in FIG. 2. The high refractive index layer was formed using TiO 2 to have a thickness of 45 nm, and the low refractive index layer was formed to have a thickness of 77 nm using SiO 2. An orientation film was formed on the inner side of the upper reflection layer 211 and the lower reflection layer 111, and the orientation film was formed with 100 nm of polyimide. The cell gap of the liquid crystal layer 3 was 480 nm, and the liquid crystal having a refractive index DELTA n of 0.2 was used. The results of the simulation under these conditions are shown in Fig.

16 shows the characteristics (light intensity according to wavelength) of light transmitted through the liquid crystal layer micro-cavity and the dielectric micro-cavity and the characteristics of the light source (wavelength dependency) in addition to the dielectric micro- Luminance) are shown and compared. The first upper layer, the second upper layer, the first lower layer and the second lower reflection layer 211, 212, 111 and 112 used in FIG. 16 have a structure as shown in FIG. 2. The high refractive index layer is formed by using TiO 2 And a low refractive index layer was formed using SiO 2 and formed at a thickness of 72 nm. A dielectric layer is disposed between the first upper reflective layer 211 and the second upper reflective layer 212 and between the first lower reflective layer 111 and the second lower reflective layer 112. Instead of the dielectric layer, a low refractive index layer and a high refractive index layer . That is, when the high refractive index layer is H, the low refractive index layer is L, and the liquid crystal layer is LC, the layered relationship is as follows.

HLH 2L HLHL HLH LC HLH LHLH 2L HLH

Here, 2L denotes a layer having a low refractive index and having twice the thickness of another refractive index layer.

In this case, the portion indicated in boldface forms the first upper reflective layer 211, the liquid crystal layer 3 and the first lower reflective layer 111, and the structure described on the outer side shows the second reflective layer and the dielectric layer. The second upper reflective layer and the upper dielectric layer and the second lower reflective layer and the lower dielectric layer have a symmetrical structure.

When the structure of H L H is grasped as a unit laminate structure, the outermost structure can be grasped as the second upper reflective layer and the second lower reflective layer, and all the remaining layers therebetween can be grasped as a dielectric layer. This case corresponds to the embodiment of Fig.

On the other hand, in the case of grasping the layer having the structure of H L H as the additional reflection layer among the layers recognized as the dielectric layers from above, it is also possible to grasp the structure in which two additional upper reflection layer and lower reflection layer are added. In this case, two additional dielectric layers are added, with a layer of 2L and L, respectively, corresponding to the two dielectric layers. In this case, unlike FIG. 10, a total of three reflective layers are disposed on one display panel, corresponding to a structure in which two dielectric layers are formed. Therefore, when an additional reflective layer is formed, two or more additional reflective layers may be formed on one display plate, unlike FIG.

The cell gap of the liquid crystal layer 3 was 730 nm, and the liquid crystal having a refractive index DELTA n of 0.2 was used. The results of the simulation under these conditions are shown in Fig.

The transmission wavelength in Fig. 15 shows a peak around a specific wavelength. On the other hand, the transmission wavelength in FIG. 16 has a peak value in a wide wavelength range. That is, when only one liquid crystal layer microcavity is included, the microcavity is transmitted around a specific wavelength. However, when the dielectric micro-cavity is further included, it is confirmed that the wavelength band to be transmitted is widened due to the characteristics of the dielectric micro-cavity.

However, in all the embodiments, the brightness of the transmitted light can be adjusted by adjusting the refractive index N of the liquid crystal layer 3, so that gradation expression is possible.

17 and 18 show the blocking and transmission characteristics of the light blocking layer 233 and the light transmitting layer 232 included in the phosphor unit 230. FIG.

First, in FIG. 17, the characteristics of the ultraviolet ray transmitting filter are shown by the transmission characteristics of the light transmitting layer 232.

On the other hand, FIG. 18 shows the characteristics of the ultraviolet cut filter due to the transmission characteristics of the light blocking layer 233.

The characteristics of light incident on the fluorescent layer 231 are enhanced by the light transmitting layer 232 and the light blocking layer 233 to prevent unnecessary light from entering the fluorescent layer 231, The fluorescent layer 231 is excited by light to emit no light so that unnecessary light is not provided to the user's eyes, thereby improving the display quality.

However, depending on the embodiment, the light transmitting layer 232 and the light blocking layer 233 may be omitted.

The refractive index N of the liquid crystal layer 3 is varied by the electric field generated by the pixel electrode 191 and the common electrode 270. The pixel electrode 191 is located on the lower panel 100, And the common electrode 270 is disposed on the upper panel 200. However, according to the embodiment, the pixel electrode 191 and the common electrode 270 may be located on the same display panel, the pixel electrode 191 may be located on the upper display panel 200, the common electrode 270 may be on the lower display panel 100). The pixel electrode 191 and the common electrode 270 are also referred to as a pair of electric field generating electrodes and are formed on at least one of the upper panel 200 and the lower panel 100.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

100: Lower display panel 110: Lower insulating substrate
111, 112: lower reflective layer 113: lower dielectric layer
121, 221: optical film 124: gate electrode
140: gate insulating film 154: semiconductor
173: source electrode 175: drain electrode
180: first protective film 185: second protective film
191: pixel electrode 200: upper panel
210: upper insulating substrate 211, 212: upper reflective layer
213: Upper dielectric layer 230: Phosphor unit
231: fluorescent layer 232: light-transmitting layer
233: light blocking layer 270: common electrode
3: liquid crystal layer 500: backlight unit
510: light source 520: light guide plate
525: reflective sheet 530: prism sheet

Claims (20)

A lower display panel including a lower insulating substrate and a lower reflective layer;
An upper display panel including an upper insulating substrate and an upper reflective layer;
A liquid crystal layer positioned between the lower reflective layer of the lower panel and the upper reflective layer of the upper panel; And
A backlight unit disposed below the lower panel and including a light source,
Generating electrodes are respectively formed on the lower panel and the upper panel and one of the pair of the electric field generating electrodes is formed on either the lower panel or the upper panel,
Wherein the lower reflective layer, the upper reflective layer, and the liquid crystal layer form micro cavities,
The luminance of the light resonated and emitted from the micro-cavity is changed by the electric field generated by the electric field generating electrode,
Wherein the liquid crystal layer is formed as one layer between the upper display panel and the lower display panel. The method of claim 1,
Wherein the voltage applied to the field generating electrode is adjusted to change an electric field to change the brightness of light emitted from the micro cavity to display the gradation. 3. The method of claim 2,
Wherein the upper reflective layer and the lower reflective layer include a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly laminated. 4. The method of claim 3,
Wherein the unit laminated structure has a triple layer structure in which the high refractive index layer is formed as two layers above and below and the low refractive index layer is interposed therebetween. A lower display panel including a lower insulating substrate and a lower reflective layer;
An upper display panel including an upper insulating substrate and an upper reflective layer;
A liquid crystal layer positioned between the lower reflective layer of the lower panel and the upper reflective layer of the upper panel; And
A backlight unit disposed below the lower panel and including a light source,
Wherein at least one of the pair of field generating electrodes is formed on at least one of the lower panel and the upper panel, or one of the pair of field generating electrodes is formed on one of the lower panel and the upper panel, All of which are formed,
Wherein the lower reflective layer, the upper reflective layer, and the liquid crystal layer form micro cavities,
The wavelength or the luminance of the light resonated in the micro cavity is changed by the electric field generated by the electric field generating electrode,
Wherein the upper reflection layer and the lower reflection layer include a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly laminated,
Wherein at least one of the upper reflection layer and the lower reflection layer has the unit laminate structure formed up and down, and a metal layer is formed therebetween. 4. The method of claim 3,
Wherein the upper display panel further comprises a phosphor unit including a fluorescent layer. The method of claim 6,
Wherein the fluorescent layer is excited by light of a specific wavelength provided by the light source to display a color. 8. The method of claim 7,
Wherein the phosphor unit further comprises a light transmitting layer positioned below the fluorescent layer and transmitting the light of the specific wavelength. 8. The method of claim 7,
Wherein the phosphor unit further comprises a light blocking layer disposed on the fluorescent layer and blocking light of the specific wavelength. The method of claim 6,
Wherein the phosphor unit is positioned between the upper insulating substrate and the upper reflective layer. The method of claim 6,
And the phosphor unit is located outside the upper insulating substrate. 4. The method of claim 3,
Wherein the electric field generating electrode includes a common electrode formed on the upper panel and a pixel electrode formed on the lower panel,
The common electrode is located on the upper reflective layer,
And the pixel electrode is located under the lower reflective layer. 4. The method of claim 3,
Wherein the electric field generating electrode includes a common electrode formed on the upper panel and a pixel electrode formed on the lower panel,
Wherein the common electrode is located below the upper reflective layer,
And the pixel electrode is positioned above the lower reflective layer. A lower display panel including a lower insulating substrate and a lower reflective layer;
An upper display panel including an upper insulating substrate and an upper reflective layer;
A liquid crystal layer positioned between the lower reflective layer of the lower panel and the upper reflective layer of the upper panel; And
A backlight unit disposed below the lower panel and including a light source,
Generating electrodes are respectively formed on the lower panel and the upper panel and one of the pair of the electric field generating electrodes is formed on either the lower panel or the upper panel,
Wherein the lower reflective layer, the upper reflective layer, and the liquid crystal layer form micro cavities,
The intensity of the light resonated in the micro cavity is changed by the electric field generated by the electric field generating electrode,
Wherein the upper reflection layer and the lower reflection layer include a unit laminate structure in which a high refractive index layer and a low refractive index layer are repeatedly laminated,
Wherein the lower display panel further comprises a second lower reflective layer positioned below the lower reflective layer,
And the upper display panel further includes a second upper reflective layer positioned on the upper reflective layer. The method of claim 14,
A lower dielectric layer positioned between the lower reflective layer and the second lower reflective layer,
And an upper dielectric layer disposed between the upper reflective layer and the second upper reflective layer. 4. The method of claim 3,
Further comprising an optical film attached to the outermost side of the upper display panel or the lowermost side of the lower display panel,
Wherein the optical film is not a polarizer. 4. The method of claim 3,
Wherein the backlight unit further comprises a light guide plate and a reflective sheet for transmitting the light provided from the light source to the lower display panel. The method of claim 17,
And a protrusion pattern is formed on a lower surface of the light guide plate. The method of claim 17,
And a prism sheet having a prism pattern on an upper portion of the light guide plate. 4. The method of claim 3,
Wherein the light source provides ultraviolet light or blue light.

Images